Explosion ahead?

An Israeli soldier looks on as a United Nations jeep drives past the Quneitra border crossing between Israel and Syria, in the Golan Heights, on the Israeli side of the 1973 ceasefire line with Syria, on Jan. 31, 2013. Israeli forces attacked a convoy on the Syrian-Lebanese border during the night as concern has grown in the Jewish state over the fate of Syrian chemical and advanced conventional weapons.

Israel’s successful Jan. 30 air attack against a Syrian military convoy received significant media attention, being the first overt Israeli intervention in Syria’s brutal and continuing civil war. However, the strike’s real implications, not well understood or reported in the press, relate less to Syria than to Iran and the threat of Israel gutting Tehran’s increasingly robust nuclear weapons program.

Although Israel has been restrained publicly, and media accounts differ, the destroyed convoy’s most likely cargo was air defense systems (in NATO nomenclature, SA-17s) being shipped to Lebanon for use by the terrorist group Hezbollah. Russia makes the SA-17s, which are mobile surface-to-air missiles, launchers and radars for bringing down bombers, fighters and cruise missiles. While not Russia’s most sophisticated air-defense system, the SA-17’s flexibility and proven capabilities make it a formidable air-defense package.

Whether the SA-17s involved here were originally sold to Syria, or whether Iran was transporting systems it owned through Syria, is not known definitively. Either way, the key connection is Iran, which is deploying its assets where they are most needed. Significantly, Tehran’s highest priority is not defending the Assad regime from potential Western or Israeli airstrikes (which are unlikely in any case) but Hezbollah and its extensive arsenal of missiles capable of targeting all of Israel’s territory.

Why does Hezbollah need such new and improved air-defense capabilities? As Israeli Prime Minister Benjamin Netanyahu forms his next coalition government, the highest security threat on Israel’s agenda is Iran’s nuclear-weapons program. True, the deadly civil war in Syria, the rise of the Muslim Brotherhood in Egypt and the continuing threat of Palestinian terrorism seem more imminent. But a deliverable Iranian nuclear weapon is an existential threat to the Jewish state, a scenario once characterized by former Prime Minister Ariel Sharon as a “nuclear Holocaust.”

Despite President Obama’s rhetoric that “all options are on the table,” there is essentially no chance he will use force preemptively to stop Iran from crossing the nuclear finish line. In fact, Vice President Biden recently repeated that the administration still believes negotiation can resolve the Iranian threat. That is why Israel has felt the pressure for years to decide whether to strike Iran preemptively — pressure now growing rapidly as Iran’s progress toward weaponization and delivery capability continues.

No one knows what Israel’s decision will be. But the timing for the decision is narrowing quickly. If Israel does not strike, Iran will have nuclear weapons and likely in the near future. And if Israel does strike, the region and the world are asking themselves how Iran will respond.

Speculation includes Iran closing the Strait of Hormuz, attacking nearby U.S. forces or Arab states across the Persian Gulf or directly retaliating against Israel. While there is always uncertainty about Tehran’s religious fanatics, these options are unlikely because they risk U.S. or further Israeli military responses that could cripple Tehran.

Instead, Iran’s most promising alternative would be having its proxies — Hamas in Gaza and Hezbollah in Lebanon — strike Israel and its vulnerable civilian targets. To suppress this missile fire, Israel would need all its air assets. And, thus, the presence of SA-17s in Lebanon constitutes a real threat to Israel’s efforts. And this might also be why Netanyahu recently ordered Iron Dome missile-defense units to northern Israel.

In the conspiracy-filled Middle East, many worry that Iran might cause Hezbollah and Hamas to attack first, thus distracting Israel and postponing any attack against Iran’s nuclear facilities. Buying time is always a high priority for nuclear proliferators like Tehran. Time is a critical asset for advancing their nuclear-weapons programs, increasing their defense capabilities and shoring up their economies against Western sanctions efforts, all of which Iran is doing.

Whatever the logic behind the destruction of the SA-17 convoy to Lebanon, however, there is no doubt that strategic tensions in the Middle East are rising quickly. As the Sept. 11, 2012, assassinations of U.S. diplomats in Libya showed, combined with the recent hostage killings in Algeria and the chaos in the streets of Egypt and elsewhere, the entire region is approaching a potential explosion.

And the most important element of all is Iran’s nuclear threat. That is Israel’s top priority. And it should be America’s, even if President Obama doesn’t get it.